<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>用户登录</title>
<style>
    * {
        margin: 0;
        padding: 0;
    }

    html, body {
        height: 100%;
        height: 100%;
    }

    .login {
        width: 358px;
        height: 588px;
        border-radius: 15px;
        padding: 0 50px;
        position: relative;
        left: 50%;
        top: 50%;
        transform: translate(-50%, -50%);
        background-color: #282c34;
    }

    .header {
        font-size: 38px;
        font-weight: bold;
        text-align: center;
        line-height: 200px;
        color: #61dafb;
    }

    .container {
        height: 30px;
        width: 250px;
        position: absolute;
        left: 50%;
        top: 40%;
        transform: translate(-50%, -50%);
    }

    .container1 {
        height: 30px;
        width: 250px;
        position: absolute;
        left: 50%;
        top: 50%;
        transform: translate(-50%, -50%);
    }

    .container {
        height: 30px;
        width: 250px;
        position: absolute;
        left: 50%;
        top: 40%;
        transform: translate(-50%, -50%);
    }

    .container2 {
        height: 30px;
        width: 250px;
        position: absolute;
        left: 75%;
        top: 56%;
        transform: translate(-50%, -50%);
    }


    input {
        width: 100%;
        height: 100%;
        position: relative;
        outline: none;
        border: none;
        box-sizing: border-box;
        padding-left: 5px;
        background-color: #282c34;
        color: #61dafb;
        caret-color: #61dafb;
    }

    input::placeholder {
        color: #61dafb;
    }

    span {
        position: absolute;
        content: "";
        display: block;
        background-color: #61dafb;
        transition: transform .1s ease-in-out;
    }

    .top,
    .bottom {
        left: 0px;
        right: 0px;
        height: 2px;
    }

    .left,
    .right {
        top: 0px;
        bottom: 0px;
        width: 2px;
        transform: scaleY(0);
    }

    .top {
        top: 0px;
        transform: scaleX(0);
        transform-origin: left center;
        transition-delay: .2s;
    }

    .left {
        left: 0px;
        transform-origin: bottom center;
        transition-delay: .3s;
    }

    .bottom {
        bottom: 0px;
    }

    .right {
        right: 0px;
        transform-origin: top center;
        transition-delay: .1s;
    }

    input:focus ~ .right {
        transform: scaleY(1);
        transform-origin: bottom center;
    }

    input:focus ~ .left {
        transform: scaleY(1);
        transform-origin: top center;
    }

    input:focus ~ .top {
        transform: scaleY(1);
        transform-origin: right center;
    }

    .btn {
        position: absolute;
        left: 50%;
        top: 55%;
        transform: translate(-50%, -50%);
        text-align: center;
        padding: 5px;
        width: 55%;
        height: 5%;
        margin-top: 40px;
        background-color: #61dafb;
        color: #fff;
    }
</style>
</head>
<body>
<div class="login">
    <div class="header">登录</div>
    <form action="/user/login" method="post">
        <div class="container">
            <input type="text" name="username" placeholder="请输入用户名">
            <span class="left"></span>
            <span class="right"></span>
            <span class="top"></span>
            <span class="bottom"></span>
        </div>
        <div class="container1">
            <input type="password" name="password" placeholder="请输入密码">
            <span class="left"></span>
            <span class="right"></span>
            <span class="top"></span>
            <span class="bottom"></span>
        </div>
        <br/>
        <div class="container2">
            <input type="checkbox" name="remember-me">
        </div>
        <input style="display: block" type="submit" class="btn" placeholder="登录"/>
    </form>
</div>
</body>
</html>